hcrypto.engines
Class PlayfairEngine

java.lang.Object
  |
  +--hcrypto.cipher.CipherEngine
        |
        +--hcrypto.cipher.BlockCipher
              |
              +--hcrypto.engines.PlayfairEngine

public class PlayfairEngine

extends BlockCipher

1. If both letters happen to be in the same row, the letters immediately to the right of each letter are used. The letter to the "right" of the last letter in a row is the first letter in that same row. For example:

2. If both letters are in the same column, the letters immediately below each letter are used. The letter "below" a bottom letter is the top letter of the same column. For example:

3. If the two letters are in different rows and in different columns, each letter is replaced by the letter in the same row that is also in the column occupied by the other letter. For example: If the keyword is "keyword", the matrix would look like this:

   k e y w o 
        r d a b c 
        f g h i l
        m n p q s
        t u v x z

TranspositionKey
Alphabet

Fields inherited from class hcrypto.cipher.BlockCipher

alphabet, blocksize

Fields inherited from class hcrypto.cipher.CipherEngine

alphabetRangeOptions

Constructor Summary

PlayfairEngine()
Creates a PlayfairEngine and sets the alphabetRangeOptions instance variable to "100000", which translates to the "az" alphabet option only.

Method Summary

java.lang.String	engineDecode(java.lang.String s) Returns an encoded String for the specified String.
java.lang.String	engineEncode(java.lang.String s) Returns an encoded String for the specified String.
protected void	engineInit(HistoricalKey hKey) Initializes the PlayfairEngine with the specified hKey.

Methods inherited from class hcrypto.cipher.BlockCipher

engineDecrypt, engineDecryptFile, engineEncrypt, engineEncryptFile

Methods inherited from class hcrypto.cipher.CipherEngine

getAlphabetRangeOptions

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PlayfairEngine

public PlayfairEngine()

Creates a PlayfairEngine and sets the alphabetRangeOptions instance variable to "100000", which translates to the "az" alphabet option only.

Method Detail

engineInit

protected void engineInit(HistoricalKey hKey)
                   throws java.lang.Exception

Initializes the PlayfairEngine with the specified hKey.

Overrides:

engineInit in class BlockCipher

Parameters:

hKey - a PlayfairKey.

engineEncode

public java.lang.String engineEncode(java.lang.String s)
                              throws java.lang.Exception

Returns an encoded String for the specified String. Characters which are not part of the chosen alphabet set are ignored.

Overrides:

engineEncode in class BlockCipher

Parameters:

s - the String to be encrypted

engineDecode

public java.lang.String engineDecode(java.lang.String s)
                              throws java.lang.Exception

Returns an encoded String for the specified String. Characters which are not part of the chosen alphabet set are ignored.

Overrides:

engineDecode in class BlockCipher

Parameters:

s - the String to be decrypted